Why can't I Multitask in Tablet Mode?

I have a new Dell Venue 8 Pro Windows 10. I can't seem to pin windows (apps) to the left or to the right to split-screen multitask in tablet mode. It works in desktop mode and when I then switch to tablet mode, with the 2 apps still pinned, they are still pinned, even with the slide bar between them to resize. Once I try pinning another app, everything goes to full screen and I cant pin to the right or left again.

I have a larger Lenovo 2-in-1 device and multitasking works just fine. I matched all the windows settings I could find that related to this, is there a 'full screen only in Tablet Mode' setting somewhere I couldn't find? Or could is this be a hardware issue? Is this happening to anyone else?

This is the latest generation (Dell Venue 8 Pro 5855) that came with windows 10 preinstalled.

I went side-by-side with my devices and started matching every single setting (not just multitask and tablet mode) from my device that worked to this device and it didn't take long; the top setting System > Display > Change the size of text, apps, and other items by default on this device was set to 200% and on my Lenovo was set to 100% (because it has a 15" screen not an 8" screen), so I changed it to match and right out of the gate it worked! By Trial and Error I got to 175% and it still worked (I can only make the scroll bar go in 25% increments). So by further trial and error I found Control Panel > Appearance and Personalization > Display > Set a Custom Level and set it up to 185% anything above that and it didn't work.